U.S. patent number 5,681,129 [Application Number 08/655,218] was granted by the patent office on 1997-10-28 for method for marking grass fields and apparatus for applying such method.
This patent grant is currently assigned to Athar International Services SA. Invention is credited to Ewald Mohring, Carlo Nicodemo.
United States Patent |
5,681,129 |
Nicodemo , et al. |
October 28, 1997 |
Method for marking grass fields and apparatus for applying such
method
Abstract
An advertising display method involves marking grass sports
fields by bending the grass blades in definite zones and bending or
leaving them straight in other zones in order to form an image or a
word. The difference in the direction given to the grass blades is
quite visible to the spectator. The grass blades are directed by
means of an apparatus mounted on rollers which runs on the grass
surface. The apparatus also has brushes and/or additional rollers
which rotate to straighten the grass blades on definite sectors.
The sectors form an image or the letters of a words. The engines
which drive the apparatus and the brushes and/or rollers are
electrical and are controlled by a computer. The image or word to
represent on the grass, as well as the position of the apparatus on
the surface to work, are entered in the memory of a computer.
Inventors: |
Nicodemo; Carlo (Cavarzere,
IT), Mohring; Ewald (Salgen, DE) |
Assignee: |
Athar International Services SA
(Tortola, VG)
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Family
ID: |
4229914 |
Appl.
No.: |
08/655,218 |
Filed: |
June 5, 1996 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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280661 |
Jul 27, 1994 |
5540516 |
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Foreign Application Priority Data
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Jul 28, 1993 [CH] |
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2273/93 |
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Current U.S.
Class: |
404/72; 404/75;
404/93; 404/85 |
Current CPC
Class: |
A63C
19/06 (20130101); A63C 19/00 (20130101); G09F
19/00 (20130101) |
Current International
Class: |
A63C
19/00 (20060101); G09F 19/00 (20060101); E01F
009/06 () |
Field of
Search: |
;47/1.01,1.5
;15/79.1,79.2 ;404/12,42,93,94,122,131,123,125,126,17,72,75,85
;56/1.2A,1.2E,16.4B,DIG.3,DIG.12,DIG.19 ;472/92 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2 085 403 |
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Dec 1971 |
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FR |
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2 567 359 |
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Jan 1986 |
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FR |
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9 319 582 |
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Oct 1993 |
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WO |
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Primary Examiner: Lisehora; James
Attorney, Agent or Firm: Bacon & Thomas
Parent Case Text
This application is a Continuation of application Ser. No.
08/280,661, filed Jul. 27, 1994, now U.S. Pat. No. 5,540,516.
Claims
We claim:
1. A method for marking grass fields, comprising the steps of
directing a part of the blades of the grass surface in one
direction, and directing or leaving at least another part of the
blades to be directed in at least one other direction so that at
least one of the parts forms a marking on the grass,
wherein the step of directing the blades of at least the part of
the grass surface comprises the step of directing blades by blade
directing means, further comprising the steps of dividing a model
of the image into several points, dividing the grass surface into
several sectors, and operating the blade directing means on the
grass in connection with the position of said blade directing means
on sectors which correspond to points of the model of the
image.
2. A method as claimed in claim 1, further comprising the step of
registering the position of said apparatus on the grass surface
through sensors which detect magnetizable bodies that are deposited
or buried at definite places on or under said grass surface.
3. A method as claimed in claim 1, further comprising the step of
registering the position of said apparatus on the grass surface by
means of a device which is able to at least receive electromagnetic
or sonic waves.
4. A method as claimed in claim 3, wherein said electromagnetic
waves are signals from geostationary satellites.
5. A method as claimed in claim 1, wherein the step of directing
the blades comprises the step of directing the blades of at least a
part of the grass surface by means of at least one brush and by
means of at least one roller.
6. A method as claimed in claim 1, wherein the step of operating of
the blade directing means comprises the step of inputting to a
computer (1) said model, (2) an instantaneous position of the
roller on the grass surface, and (3) instructions which operate the
brush in each sector based on the corresponding point of the model
and the position of the roller.
7. A method as claimed in claim 6, further comprising the step of
registering the position of said apparatus on the grass surface
through sensors which detect magnetizable bodies that are deposited
or buried at definite places on or under said grass surface.
8. A method as claimed in claim 6, further comprising the step of
registering the position of said apparatus on the grass surface by
means of a device which is able to at least receive electromagnetic
or sonic waves.
9. A method as claimed in claim 8, wherein said electromagnetic
waves are signals from geostationary satellites.
10. A method as claimed in claim 1, wherein the step of directing
the blades comprises the step of directing the blades of at least a
part of the grass surface by means of at least one roller.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of mass communication
techniques, and more particularly to advertising display
technologies and to the exploitation of surfaces, such as sports
fields, which have not previously been used for advertising
displays.
2. Description of the Prior Art
During events which take place on grass fields, in particular
sports events, many advertising panels usually border the field.
The grass itself, however, although it is the place that the public
sees most frequently, and is the largest surface that the
spectators have before their eyes, does not carry any
advertisements. The only marks which are printed on the grass are
those related to the sport played on the field.
SUMMARY OF THE INVENTION
It is accordingly an objective of the invention to utilize the
previously unused surface of a sports field for advertising display
purposes by making possible the marking of messages, especially
advertising messages, on the grass surface itself, without creating
confusion with the sport markings.
It is another objective of the invention to provide a method for
marking the grass with signs, such as letters forming words, names
or numbers, or images, and to provide an apparatus capable of
making such markings.
The invention has both method and apparatus embodiments.
In a first method embodiment of the invention, a preferred method
of marking grass fields, especially sports fields, involves
directing a part of the blades of a grass surface in one direction,
and orienting or leaving oriented in at least one other direction
at least another part of the blades of the grass surface so that at
least one of the parts constitutes an image or sign.
In a second method embodiment of the invention, the method of the
first embodiment is implemented by orienting the blades of at least
a part of the grass surface by means of one or several brushes.
In a third method embodiment of the invention, the method of the
second embodiment is implemented by using rotating brushes.
In a fourth method embodiment of the invention, the method of the
first embodiment is implemented by orienting the blades of at least
a part of the grass surface by means of one or several rollers.
In a fifth embodiment of the invention, the method of the first
embodiment is implemented by orienting the blades of grass surfaces
by means of one or several brushes and by means of one or several
rollers.
In a sixth embodiment of the invention, the method of the three
last above described embodiments involves dividing the model of the
image or sign to be marked on the grass surface into several
points, dividing the grass surface into several sectors, and
commanding the action, and especially the lowering, the raising
and/or the rotation of the brushes and/or the rollers in connection
with the position of the brushes and/or rollers on definite sectors
which correspond to definite points of the model of the sign or
image to be marked on the grass surface.
In a seventh embodiment of the invention, the method of the last
above described embodiment involves commanding the action, and
especially the lowering, the raising and/or the rotation of the
brushes and/or rollers, using a computer in which are inserted the
model or models of the signs or images to mark on the grass
surface, the model or models being divided in several points, the
position of the brushes and/or rollers with regard to the position
of the sectors of the grass surface and instructions which command
the action with regard to the position of the brushes and/or
rollers.
In a further version of the above described seventh embodiment of
the invention, the preferred method involves using an apparatus on
which are fixed the brushes or rollers, registering the position of
the apparatus on the grass surface through sensors which detect
magnetizable bodies that are deposited or buried at definite places
on or under said grass surface.
In a further version of the above described seventh embodiment of
the invention, the preferred method includes the steps of using an
apparatus on which brushes or rollers are fixed and registering the
position of the apparatus on the grass surface by means of a device
which is able to emit and receive electromagnetic or sonic
waves.
In a particular embodiment of that latter version, the device is
able to receive signals from geostationary satellites.
The preferred apparatus for marking grass fields, in a first
embodiment, includes wheels for moving the apparatus, brushes
and/or rollers, and means for lowering down to the grass and
raising from the grass, so that they do not touch grass any more,
at least some of said brushes and/or rollers.
In a second apparatus embodiment, the preferred apparatus includes
brushes which rotate and means for making the brushes rotate in two
directions.
In a third embodiment of the preferred apparatus, which is a
variant of the second embodiment, the apparatus includes means for
lowering down to the grass and for raising from the grass, so that
they do not touch the grass any more, at least some of the rotating
brushes.
In a fourth embodiment of the preferred apparatus, the brushes
and/or rollers according to one of the above apparatus embodiments
are assembled in groups.
In a fifth embodiment of the preferred apparatus, at least a part
of the rollers are mounted on one or more rotating barrels so that
they can freely rotate.
In a sixth embodiment of the preferred apparatus the brushes and/or
the rollers and/or the groups of brushes and/or rollers are
staggeredly fixed to the apparatus.
In a seventh apparatus embodiment, the preferred apparatus
according to one of the above described embodiments includes means
for raising the wheels, and rollers which are able to support and
to move the apparatus when the wheels have been raised up.
In an eighth apparatus embodiment, the preferred apparatus
according to the seventh above described embodiment includes at
least one engine which sets in motion the rollers which support the
apparatus and a steering device for directing the apparatus when
the wheels have been raised up.
In a ninth apparatus embodiment, the preferred apparatus according
to the seventh or the eighth embodiments involves an arrangement
for setting each roller or group of rollers and each brush or group
of brushes in motion by a separate engine.
In a tenth apparatus embodiment, the preferred apparatus according
to one of the above described embodiments comprises an odometer
actuated by the rollers which support the apparatus or by a wheel
which rolls on the grass surface and which registers the position
of said apparatus on said grass surface.
In an eleventh apparatus embodiment, the preferred apparatus
according to one of the four last above described embodiments is
characterized in that the rotation axes of the wheels are
perpendicular to the rotation axes of the rollers and/or
brushes.
According to a variant of all of the above described apparatus
embodiments, the preferred apparatus includes a computer in which
the model or models of the image or images or of the sign or signs
to be marked on the grass surface, as well as the position of the
apparatus on the grass surface, are entered in the computer, the
apparatus further including means by which the computer can actuate
the brushes and/or the rollers according to the entries so that at
least a part of the blades of the grass surface are oriented in a
direction which is different from the direction of the other
blades, so that at least a part of the grass surface constitutes an
image or a sign which corresponds to the image or to the sign
entered in the computer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic plan view of an apparatus according to a
preferred embodiment of the invention.
FIG. 2 is a schematic lateral view of the apparatus shown in FIG.
1.
FIG. 3 is a schematic plan view of an apparatus according to a
further embodiment of the invention.
FIG. 4 is a schematic lateral view of the preferred apparatus shown
in FIG. 3.
FIG. 5 is a schematic plan view of a variant of the preferred
apparatus shown in FIG. 3, in which the brushes are staggeredly
placed.
FIG. 6 is a schematic lateral view of the preferred apparatus shown
in FIG. 5.
FIG. 7 is a schematic plan view of a variant of the preferred
apparatus shown in FIGS. 1 and 2, in which the brushes have been
replaced by rollers.
FIG. 8 is a schematic lateral view of the preferred apparatus shown
in FIG. 7.
FIG. 9 is a schematic plan view of a variant of the apparatus shown
in FIGS. 7 and 8, in which the rollers are staggered.
FIG. 10 is a schematic lateral view of the preferred apparatus
shown in FIG. 9.
FIG. 11 is a schematic plan view of a further embodiment of the
variant shown in FIGS. 7 and 8, in which the rollers are mounted on
rotating barrels.
FIG. 12 is a schematic lateral view of the preferred apparatus
shown in FIG. 11.
FIG. 13 is a schematic plan view of the apparatus shown in FIGS. 11
and 12 in which the rotating barrels bearing the rollers are
staggered.
FIG. 14 is a schematic lateral view of the apparatus shown in FIG.
13.
FIG. 15 is a schematic plan view of a further embodiment of the
preferred apparatus, in which the rollers which do not support the
apparatus are mounted on rotating barrels.
FIG. 16 is a schematic lateral view of the preferred apparatus
shown in FIG. 15.
FIG. 17 is a schematic plan view of a variant of the preferred
apparatus shown in FIGS. 15 and 16, in which the rotating barrels
bearing the rollers have been staggered.
FIG. 18 is a schematic lateral view of the preferred apparatus
shown in FIG. 17.
FIG. 19 is a schematic plan view of a variant of the preferred
apparatus shown in FIGS. 15 and 16, in which the rotating barrels
have been fixed on both sides of the supporting rollers.
FIG. 20 is a schematic lateral view of the preferred apparatus
shown in FIG. 19.
FIG. 21 is a schematic plan view of a variant of the preferred
apparatus shown in FIG. 15, in which the non-supporting rollers
mounted on rotating barrels have been replaced by rotating
brushes.
FIG. 22 is a schematic lateral view of the preferred apparatus
shown in FIG. 21.
FIG. 23 is a schematic plan view of a variant of the preferred
apparatus shown in FIG. 17, in which the rotating barrels which
bear rollers have been replaced by rotating brushes.
FIG. 24 is a schematic lateral view of the preferred apparatus
shown in FIG. 23.
FIG. 25 is a schematic plan view of a variant of the preferred
apparatus shown in FIG. 19, in which the rotating barrels which
bear rollers have been replaced by rotating brushes.
FIG. 26 is a schematic lateral view of the preferred apparatus
shown in FIG. 25.
FIG. 27 is a plan view of a variant of the preferred apparatus
shown in FIG. 25, in which the rotating brushes have been staggered
and the power of the engine is transmitted through belts.
FIG. 28 is a cross section according to A--A of the preferred
apparatus shown in FIG. 27.
FIG. 29 is a cross section according to B--B of the preferred
apparatus shown in FIG. 27.
FIG. 30 is a cross section according to C--C of the preferred
apparatus shown in FIG. 27.
FIG. 31 is a diagram of an electronic and electric command device
for the preferred apparatus.
FIG. 32 shows a grass surface divided into several sectors with a
mark imprinted with dots in chosen sectors, the whole of the dots
forming the mark.
FIG. 33 shows a network of metallic cables or wires which is buried
under the grass surface and which allows positioning the apparatus
on the grass surface.
FIG. 34 shows a sports field with four surfaces to mark and two
tranceivers which allow positioning the apparatus on the grass
surface.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the embodiment schematically shown in FIGS. 1 and 2, the
apparatus according to the invention is equipped with four wheels 1
and with a range of brushes 2, the bristles of which are vertically
directed towards the grass. The wheels are used to move the
apparatus to the grass surface to the work area to be marked, and
to move it on the surface. The wheels are moved by one or several
engines, which are preferably electrical, and which are not shown
here, and are equipped with a steering device. Each brush can be
lowered down to the grass and raised above the grass by raising and
lower means 16. When the apparatus passes onto the grass surface to
work, the brushes are lowered down when necessary. Each brush
preferably has a width which corresponds to that of a definite
sector of the surface to be worked.
In a preferred method embodiment utilizing this simple apparatus,
the grass surface to be marked is handled like a network of small
sectors 13, which are preferably quadrangular, as shown in FIG. 32.
If the width of the surface be marked is larger than the length of
the row of brushes, it is useful to work the surface in several
parallel strips 14, the width of which corresponds to the length of
the range of brushes of the apparatus. The grass surface shown in
FIG. 32 is so divided into four strips, the width of which
corresponds to eight sectors, this latter number corresponding
itself to the number of brushes with which the apparatus is
equipped.
In operation, the apparatus rolls along the first strip and, when a
brush passes over a sector to be marked, it is brought down to the
grass and directs the grass blades as it goes by, up to the moment
when it is raised up above the grass. FIG. 32 shows that, on the
fourth strip, the third brush of the range is brought down on the
twelfth and the thirteenth sectors from the left, and is raised
afterwards, so marking the grass of the two sectors by directing
their grass blades. A part of the letter A is thus imprinted in the
grass.
The rest of the grass surface can of course remain as it was
before, without any treatment. However, it is much preferable to
have the apparatus pass a first time with all the brushes down, in
one way, in order to direct all the grass blades on the whole
strip. Afterwards, the apparatus runs on the same strip in the
other direction, and the brushes are brought down only on the
sectors which compose the sign or the image to be depicted. In that
way, the blades are directed, approximately, in only two
directions, which gives a sharper image. Once the first strip has
been worked, the apparatus is put again on the starting line, at
the beginning of the second strip, which is parallel and adjacent
to the first strip, and the process is started again, until the
whole grass surface is worked.
In the embodiment of FIGS. 3 and 4, the brushes 2 are still in one
row, but they can rotate independently from each other in either
direction. Likewise, the brushes can be braked or stopped, or can
rotate freely, independently from each other. When a brush is
locked or is rotating backwards, the grass blades bow in the
direction of the run of the apparatus. When a brush is rotating
forward, at a speed which is greater than the speed of the
apparatus, the grass blades bow in an opposite direction. The
apparatus can therefore work a whole strip in one pass. When the
apparatus reaches the end of a strip, it turns back and immediately
starts working the next strip, in the opposite way.
On the way to the surface to be marked, one can let the brushes
rotate freely, if the apparatus is not equipped with a device by
means of which the brushes can be raised up. In certain cases, it
might, however, be useful to equip the apparatus with such a brush
raising device.
FIGS. 5 and 6 show an embodiment in which the brushes are
staggeredly fixed to the apparatus, which makes assembly of the
transmissions and control devices easier, and makes it possible to
work the whole grass surface, without any gaps. An automatic
device, of a conventional type, makes the brushes work at the right
time, in spite of their staggered position.
In the embodiment shown in FIGS. 7 and 8, the row of brushes is
replaced by a row of rollers 3 which are mounted on their axes so
that they can freely rotate. In the embodiment of FIGS. 9 and 10,
the rollers are staggered and fixed. An automatic device, of a
conventional type, makes it possible to lower respective rollers at
the right time in spite of their staggered position. The rollers of
FIGS. 7 and 8 have a central division which makes it possible to
support the rollers on central bearings or ball bearings, while the
rollers of FIGS. 9 and 10 are supported by bearings which are
placed on each side of the rollers. In both embodiments, the
rollers are mounted on a device 16 which makes it possible to bring
them down and raise them up independently from each other. In both
embodiments, the functioning of the apparatus is the same as that
of the apparatus shown in FIGS. 1 and 2. In other words, it is
necessary to make the apparatus pass twice on the same strip if one
wishes to work the whole surface.
In the embodiment shown in FIGS. 11 and 12, the row of brushes
shown in FIGS. 3 and 4 is replaced by a row of rotating barrels 15
on the periphery of which rollers 3 are mounted so that they can
freely rotate around axes which are parallel to that of the barrel.
The barrels 15 can rotate in two ways, or be braked or stopped,
independently from each other, by means of engines which are not
shown. When a barrel is stopped or rotates backwards, the grass
blades lean in the same direction as the run of the apparatus. When
the barrel rotates forward, at a speed which is higher than that of
the apparatus, the grass blades lean in an opposite direction. The
apparatus can therefore work a whole strip in one way. When it has
arrived at the end of a strip, it turns back and immediately begins
to work the next strip, in the opposite way. The apparatus is
preferably equipped with a device which makes it possible to raise
the barrels in order to avoid damage to them during the way to and
from the grass surface.
FIGS. 13 and 14 show a version of this latter embodiment, in which
the rotating barrels 15 are staggeredly placed with the advantages
mentioned above in connection with FIGS. 5 and 6. In this version,
the device adapts the functioning of the barrels to the space which
is between the barrels.
In the embodiment schematically shown in FIGS. 15 and 16, the
apparatus has eight barrels 15 which bear rollers 3, and moreover
has four rollers 3 arranged in pairs. The axes of the wheels 1 are
perpendicular to the axes of the rollers. The apparatus has means
for raising the wheels, so that the apparatus can be supported by
the two pairs of rollers. The apparatus is brought to the grass
surface to be marked by means of the wheels which are down. When
the apparatus has arrived, the wheels are raised up and the
apparatus moves perpendicularly to its direction of arrival on the
grass surface by means of the two pairs of rollers which are driven
by one or more engines. The two rollers of each pair are separated
by a small space which avoids friction. It is easy to make the
apparatus turn by braking the rollers located on the same side of
the apparatus, which is possible by means of a differential mounted
on the transmission. A differential is not necessary in the case
when each roller is driven by a separate engine.
The device which makes it possible to raise and to lower the wheels
is not shown here. It is a conventional device, like many others
which have been in existence for decades in some models of trucks
(semi-trailers) or planes (landing gears).
The length of each pair of rollers and of the rotating barrels 15
corresponds to the width of a strip 14 of the grass surface. All
the blades of the grass of the strip are first directed by the
supporting rollers in the direction of the run of the apparatus.
Then, the rotating barrels pass and give a different or an
identical direction to the blades, depending on the direction and
speed of their rotation, as explained in connection with FIGS. 11
and 12. A strip can therefore be worked in one way. However, if one
wishes to work the next strip on the way back, it is necessary to
turn the apparatus around in order to avoid deletion by the
supporting rollers of the markings made by the rotating barrels, as
the supporting barrels would follow the rotating barrels if the
apparatus was not turned around.
FIGS. 17 and 18 show a variant of this latter embodiment, in which
the rotating barrels are staggered to obtain the advantages
mentioned in connection with FIGS. 5 and 6, and 13 and 14. In this
variant, a device also adapts the functioning operation of the
barrels to the space which is between the two rows of barrels.
FIGS. 19 and 20 show a variant of the embodiment of FIGS. 15 and
16, in which the two pairs of supporting rollers are bordered on
two sides by two rows of rotating barrels which bear rollers. The
presence of a row of barrels on each side of the supporting rollers
makes it possible to mark the next strip on the way back, without
turning back the apparatus. In principle, however, it is preferable
to work each strip in the same way to obtain as uniform a direction
as possible for the grass blades.
In a variant which is not shown here, the apparatus in the
embodiment of FIGS. 19 and 20 has rotating barrels staggeredly
mounted, with the above described advantages.
FIGS. 21 to 26 show variants of the embodiments shown in FIGS. 15
to 20, in which the barrels have been replaced by rotating brushes.
Like the barrels in the preceding embodiments, each rotating brush
can rotate in either direction independently of the other
brushes.
FIGS. 27 to 30 show the features of the apparatus schematically
shown in FIGS. 25 and 26, with the difference that the brushes are
staggered, with all of the advantages noted above deriving from
such arrangement.
Each rotating brush 2 can freely rotate around the axis 7 and is
driven by a belt 4 which drives the brush by means of a pulley 10
which is attached to the brush. Each belt 4 is driven by an engine
11, which is preferably electrical, and which is independent of the
other engines. The brushes are placed at such a height that they
penetrate the layer of grass, but do not touch the soil. The axes 7
which support the brushes are fixed by their ends to the main
chassis 5. Each pair of supporting rollers is supported by an axis
6. The supporting rollers freely rotate around the axis. At each
end of each axis are pulleys 10 each pulley being fixed to a
supporting roller 3. Belts 4 transmit the rotation of the engines
to the rollers. Each belt is driven by an independent engine 11.
Each engine drives the belt through a train of gears 12. The axes
which support the rollers, as well as the engines and the trains of
gears, are fixed to a secondary chassis 8. This secondary chassis 8
is fixed to a main chassis 5 through the medium of a ball bearing 9
which makes it possible for the secondary chassis to turn in a
small angle to steer the apparatus. As each roller is driven by an
independent engine, a differential is superfluous.
The engines are electrical and are powered by an accumulator. Of
course, other types of engines could be used, but they would be
less convenient. Likewise, it would be possible to use transmission
means other than belts and pulleys, for example chains or
gears.
The engines and the transmissions which drive the rollers give the
apparatus, thanks to a high gear reduction, a speed which is
approximately constant, and which is equivalent to that of a
walking man even if the weight changes.
The engines for the rollers are started manually, by switches
commanded by the driver. For the first strip, the driver can
manually command the steering device, which makes it possible to
make the two secondary chassis pivot with regard to the main
chassis. For the next strips, the computer automatically steers the
apparatus.
Each of the engines which drive the brushes is controlled and
actuated by a computer according to the position of the brushes on
the grass surface. The data which are transmitted to the computer
are registered on a RAM card. FIG. 31 gives a diagram of the
relations between the various electric or electronic devices which
drive the apparatus. The torque necessary to make a brush rotate,
whether in a direction corresponding to the direction of the
apparatus or in the contrary direction, is more or less constant,
depending on the elasticity of the bristles of the brush.
In comparison with the above described versions in which the wheels
cannot be raised up, the advantage of this preferred embodiment
lies in a better distribution of the weight, preventing the wheels
from marking furrows in the ground. In comparison with the versions
in which the brushes are replaced by barrels with rollers, this
embodiment avoids the large weight and dimensions of the
barrels.
Of course, in each contemplated embodiment, the number of devices
may vary according to the needs of the user, including the number
of rollers, barrels, brushes, engines, pulleys or wheels.
In the preferred embodiments, the method for marking grass fields
is automatically carried out by a computer. The image or images, or
the sign or signs, for example a name or a word constituting a
trademark, which must be printed on the grass, are entered in the
computer. The image or images and/or the sign or signs are marked
at points which correspond to a division of the grass surface into
several sectors 13.
The driver first places the apparatus on the starting line 15, and
then drives it manually along the first strip. The apparatus is
equipped with a device which deposits small balls made of
ferromagnetic metal on an edge of the strip, i.e. on the left of
the apparatus in the embodiment shown in FIG. 33, at regular
intervals, for example at the limit of each sector 13. The
apparatus is moreover equipped with magnetic sensors which are
connected to the computer, and with a magnetic device by means of
which the balls are recuperated on the way. The balls are deposited
in the path of the apparatus on the first strip. The computer
commands the dropping of the balls and actuates the brushes and/or
rollers at the moment when the apparatus is in a definite
position.
In order to determine this position, on the first pass, the
preferred method is to use an odometer which is connected and
driven by one or more rollers which support the apparatus, or by a
wheel attached to the apparatus and which freely rolls on the
grass. The odometer may be a common odometer of the type used, for
example, in automobiles. The odometer transmits its data to the
computer, which transmits its instructions to the engines according
to the program entered by the driver. During passage on the second
strip, the sensors transmit to the computer the data they collect
concerning the position of the apparatus with regard to that of the
balls, so that the odometer is no longer required. The position of
the balls not only defines the direction given to the apparatus,
but also the moment when the brush or roller must be actuated to
give the grass blades the required direction in a definite sector,
as well as the positions at which the balls are to be deposited in
a new line along the second strip.
As the apparatus recovers the balls deposited on the edge of the
first strip, it deposits balls on the edge of the second strip. Of
course, these balls can be the same balls which are transferred by
the apparatus from the border of the first strip to the border of
the second strip. After having worked the second strip, the driver
again places the apparatus on the starting line, at the beginning
of the next strip and the process starts again. When the apparatus
has arrived at the last strip, the computer stops the ball
depositing device, while the ball collecting device still collects
the balls deposited on the border of the preceding strip.
In another embodiment of the preferred method, the computer
commands the marking of a line in the grass, on the edge of the
strip. On the next strip, the driver drives the apparatus along the
marked line. The line is preferably marked in such a way that the
passing of the apparatus for the working of the next strip deletes
it. In other words, it is necessary that the apparatus passes along
the marked line. At the same time as the apparatus deletes this
first line, it makes a second one, at the edge of the second strip.
This second line is deleted by the passing of the apparatus on the
third strip. The process starts again until the whole surface has
been worked.
A further embodiment of the preferred method involves burying in
the ground, some centimeters under the surface, a metallic network
which corresponds to the edges of the strips and to the starting
and arrival lines, as shown in FIG. 33. The apparatus is equipped
with sensors which transmit the position of the apparatus to the
computer. A measuring device informs the computer and the driver of
any difference between the real position and the desired position
entered in the computer. Here too, the steering can be automatic or
manual.
In a further embodiment of the preferred method, transceivers are
placed on the ground and on the apparatus. Such devices can measure
the distance and/or the angle which makes it possible for the
computer to calculate the position of the apparatus with regard to
the transceivers placed on the ground. FIG. 34 schematically shows
that such transceivers could be placed at points A and B. Either
microwave, ultrasonic, or infrared transceivers could be used in
such a system. Here too, the steering can be automatic or
manual.
Lastly, it is possible to use a system in which transceivers are on
satellites, as is the case with the GPS system. Other embodiments,
modifications, and variations thereof will also occur to those
skilled in the art, and thus it is intended that the invention not
be limited by the above description, but rather that it be defined
solely by the appended claims.
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